1. Field of the Invention
The present invention relates to an image forming apparatus, an image forming system, an image forming control apparatus and a control program. Particularly the present invention relates to an image forming apparatus, an image forming system, an image forming control apparatus and a control program, which are capable of shifting a body text portion of a document to form the image.
2. Description of the Related Art
In recent years, an image forming apparatus, into which a bookbinding system is installed, is disclosed, for example, in Japanese Patent Application Open to Public Inspection No. 2004-209869. The image forming apparatus is capable of binding a book through an online network. In such an image forming apparatus, a cover sheet and a body text portion of a book can be collectively formed into an image. In the image forming apparatus, the image formation is conducted so that the document image having a predetermined size and register marks T indicating the cutting position located at the outside of the four corners of the document and the outside of the predetermined size are formed into an image on a wide paper sheet which is a little bit larger than the predetermined size. Thus it is possible to correctly cut the cover sheet and the text portion of the book after the bookbinding based on the register mark. For example, FIG. 11 illustrates the relationship between the document image position and the register marks after the image formation of the cover sheet and the body text portion of the book. As shown in FIG. 11, in the case that a cover sheet document image 101 and a body text portion document image 102 are respectively disposed on the center of a paper sheet L1 and a paper sheet L2, it is necessary to cut four sides of respective paper sheets L1 and L2. In the case of a bookbinding system utilizing online network, there is a case that the cutting portion of the body text page L2, which is going to be fixed onto a spine cover, is not cut. In order to respond to this type of bookbinding system, as illustrated in FIG. 12, an image forming apparatus for forming the image while shifting the document images 101 and 102 to the edge portion, which is going to be fixed onto the spine has been developed.
However, in the case that the image forming apparatus is one, which is capable of shifting the document images 101 and 102 to one edge, the cover sheet document image 101 also shifts the same distance as the shift amount of body text of the document image 102. As a result, the cover sheet document image 101 is shifted to one end. Thus, the center of the document image 101 of the cover sheet shifts and there is a possibility that the body text page L2 is not fixed at the correct position of the cover sheet.